Question

Which of the following is an example of alien species invading a new ecosystem resulting in biodiversity losses?

• A. Introduction of Nile Perch into lake Victoria in east Africa
• B. All of the above
• C. Introduction of Water Hyacinth into India
• D. Introduction of African Catfish into Indian waters

Answer 1

Answer: (B)

When alien species are introduced unintentionally or deliberately for whatever purpose, some of them turn invasive and cause decline or extinction of indigenous species. Examples:-

A) The Nile perch introduced into Lake Victoria in East Africa led eventually to the extinction of an ecologically unique assemblage of more than 200 species of cichlid fish in the lake.

B) Great environmental damage was caused to our native species by invasive weed species like carrot grass (Parthenium), Lantana and water hyacinth (Eicchornia).

C) The recent illegal introduction of the African catfish Clarias gariepinus for aquaculture purposes is posing a threat to the indigenous catfishes in our rivers.

So, the correct answer is 'All of the above'.